Steering of craft



Qcfilc 193%0 H. n. BECKER STEERING CRAFT Filed May 20, 1956 n 9 M w m. r msfiwm I .t a e f 1 v m I A o W 2 b, F

.m F I} R A W V A m D Fi FT Patented Oct. 4, 1938 UNlTED STATES PATENT OFFICE STEERING OF. CRAFT New York Application May 20, 1935, Serial No. 80,735

7 Claims.

My invention relates to apparatus useful in the steering of a craft with respect to a particular radiation. For example, it may be desired that the craft shall be kept on a course directed to ward or away from the source of radiation or the desired course may make some definite angle with respect to source of radiation. In certain cases the radiation employed may comprise those visible wavelengths which constitute light; in other cases I may prefer to employ some of the invisible wavelengths having properties, such as fog penetration, not possessed by light. It is the object of my invention, therefore, to provide improved apparatus useful in the steering of a craft in the above-indicated manner.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1 is a circuit diagram illustrating one embodiment of my invention; Fig. 2 shows various wave forms present in the apparatus shown by Fig. 1; Fig. 3 illustrates a modification of what is shown in Fig. l; and Fig. 4 like Fig. 2 shows various wave forms present in the modified form represented by Fig. 3.

In Fig. l of the drawing I and 2 represent two similar radiation responsive devices which are mounted on the craft, not shown, to be steered, and are arranged in such .a manner that they are adapted to receive radiation from a certain source. For the purposes of illustration I have shown these devices as photoelectric tubes but it is to be understood-that radiation responsive devices of various other forms may be used depending upon the character of the radiation to which they are intended to be responsive. Devices l and 2 are supplied with alternating current having a symmetrical wave form. Such a wave may be supplied by various well known devices of which the one that I have chosen to show in the present illustration is an oscillation generator which is adapted to produce a wave preferably of approximately 800 cycles per second. The generator is shown as comprising the electron discharge tube 3, the transformer 4, and the adjustable transformer 5 across the primary of which is connected the capacitor 6 all connected together and to suitable voltage sources in a well known manner. This oscillation generator supplies alternating current to the radiation responsive devices through the transformer l, the secondary of which is connected in series with the primary of the transformer 8 and with the devices l and 2 connected in parallel with each other. Devices 5 and 2 are also reversed one with respect to the other, that is, the anode and cathode of device l connects directly with the cathode and anode respectively of device 2.

As a result of this arrangement, it will be seen that if both devices i and 2 receive the same amount of radiation the current flowing in the primary of the transformer 8 will have equal positive and negative half cycles inasmuch as the generator supplies alternating current having a symmetrical wave. If, however, the radiation received by one device is greater than that received by the other the current in the primary of transformer 8 will have a greater amplitude for the half cycle passed by the device subjected to the greater radiation than for the other half cycle. This may be more readily understood by referring to Fig. 2 where the curve it represents the symmetrical voltage wave applied to the devices l and 2. If both devices receive the same amount of radiation the current flowing in the primary of transformer 8 will likewise have a symmetrical form. If, however, one of the devices, for example, device l, which it will be assumed passes the positive half cycles of applied current receives greater radiation than device 2, then the current traversing the primary of transformer 8 may have the asymmetrical form shown by curve H where the positive half cycle has a much 9 greater amplitude than the negative half cycle. Similarly if device 2 receives greater radiation than device I the current traversing the primary of transformer 8 might have the asymmetrical form shown by the dotted line it where the negative half cycle is greater than the positive half cycle.

As the resulting asymmetrical waves thus obtained are of very small. magnitude, it is desirable that they be suitably amplified before being 40 applied to a responsive device which I am about to describe. For so amplifying the asymmetrical waves I have shown a three-stage amplifier, which may be of any well known form, and which I have represented as comprising the three electron discharge amplifier tubes i i, 55, and i6, tubes M and !5 being connected by means of the capacitor ll, tubes is and iii being connected by means of the transformer l8. By means of the transformer 3 a voltage wave is applied to the control grid of amplifier tube M, the secondary of the transformer being shunted by the variable capacitor [9.

The output of the last tube 55 of the amplifier after being passed through the transformer 20,

which preferably is a step-down transformer, is used to operate the electroresponsive device in one direction or the other in accordance with whether the positive or negative half cycles have the greater maximum value, hence whether device I or device 2 is receiving the greater amount of radiation. The electroresponsive device which I have chosen to illustrate is a well known form of zero center indicating meter 2|. Current flow through the meter 2| in one direction causes the pointer 22 thereof to deflect to one side of the zero and likewise current flow in the opposite direction shall cause the pointer to deflect to the other side of zero.

Connected in series with the secondary of transformer 29 and the meter 2| is the nonlinear resistor 23. This resistor preferably is of the type described in United States Letters Patent No. 1,822,742 to K. B. Mc'Iachron September 8, 1931, such a resistor being commercially known as Thyrite. The resistance and current relationship of such a non-linear resistor can be expressed in the form of the hyperbolic equation, RI =C, Where R is the resistance, I is the current, and C and a are constants, the latter being less than unity. This material has the peculiar property of reacting substantially instantaneously to asymmetrical wave shapes so that a direct current may be obtained therefrom, but when symmetrical waves are applied to it no direct current results. In the apparatus thus described the direct current flow through the indicating meter 2| will be in a direction, such for example as will move the pointer to the right, if the radiation responsive device I is receiving the greater amount of radiation and will move to the left if radiation responsive device 2 is receiving the greater amount of radiation. If both devices I and 2 receive the same amount of radiation the pointer 22 will remain on zero. I preferably employ the bypass capacitor 24 which being connected in shunt with the indicator 2! serves to bypass any alternating current which may pass through the non-linear resistor 23. Instead of employing the direct current received from the non-linear resistor 23 for operating the indicating device 2| I may employ it for the operation of an automatic steering device of any well known form where the polarity and the amount of direct current control the direction taken by the craft.

In that form of my invention shown by Fig. 1 it is assumed that the radiation received is relatively uniform in value. In the modified form shown by Fig. 3 the source of radiation is intermittent or pulsating. Radiation of such a character may be produced, for example, by the use of a neon lamp excited by an alternating current. The radiation responsive devices I. and 2 in this case may be photo-electric tubes as in Fig. 1 but are excited by direct current which, for example, may be supplied by the battery 21. Opposite ends of the battery are shown connected respectively with the cathode of device I and the anode of device 2 and the midpoint of the battery is shown connected through the reactor 28 with the anode of device I and the cathode of device 2. If with this arrangement both devices I and 2 receive the same amount of radiation there will be no current flow through the reactor 28. However, if the radiation impulses reaching device I, for example, are greater than those reaching device 2, the current flow through the reactor will be greater in one direction than that in the other direction, and vice versa if device 2 receives greater radiation than device I. The potential difference across the reactor 28, which is shunted by the capacitor I9, is amplified by a three-stage amplifier comprising tubes I4, I5, and I6 as in Fig. 1 and the output circuit of the last amplifier connects through the transformer 20, the non-linear resistor 23 with the right and left zero center indicator 2I, all as in Fig. 1.

In Fig. 4 I have represented at 30 the pulses of the intermittent radiation received from the distant source which as pointed out above may comprise one or more neon lamps operated on an alternating current circuit. If device I, for example, receives a greater amount of the radiation than device 2 the wave of potential difference across the reactor 28 and the capacitor I9 due to the current passing the reactor and the effect of the capacitor may take the asymmetric form shown by the curve 3|. Likewise if device 2 receives the greater amount of radiation the wave of potential difference may have the asymmetric form shown by curve 32. These curves while differing somewhat in form from the corresponding curves II and I2 of Fig. 2 due to the squarewave form 30 of the radiation impulses and the distorting effect of the reactor 28, nevertheless have a characteristic common thereto in that the maximum value of one half cycle is greater than that of the other in accordance with which of the two radiation devices receives the greater amount of radiation. The asymmetrical voltage waves after being amplified by the three-stage amplifier and applied to the circuit including the non-linear resistor 23 produces a direct current in one direction or the other resulting in a right or left deflection of the pointer of the indicator 2| just as in the case of the apparatus shown in Fig. 1. Inasmuch as the radiation responsive devices of that form of my invention shown by Fig. 3 are supplied by continuous direct current, the pointer of the indicator 2| will not be deflected in response to radiation which is uniform and continuous but requires the use of radiation of an intermittent character.

I have chosen the particular embodiments described above as illustrative of my invention and it will be apparent that various other modifications may be made without departing from the spirit and scope of my invention which modifications I aim to cover by the appended claims.

What I claim as new anddesire to secure by Letters Patent of the United States is:

1. Incombination, means including a plurality of radiant energy responsive devices for produc ing an alternating current whose positive and negative half cycles are proportional to the relative amounts of energy received by said devices, means for amplifying said alternating current, a device operative in one direction or the other in response to the polarity of the current supplied thereto and a non-linear resistor connected in circuit with said device and said amplifying means.

2. In combination, means including a plurality ofsimilar radiation responsive devices for producing an unsymmetrical alternating voltage wave Whose positive and negative half cycles vary in accordance with the relative amounts of radiation received by said devices, an electro-responsive device operable in one direction or the other in accordance with the polarity of the current supplied thereto, a non-linear resistor connected in a series circuit therewith and means for amplifying said unsymmetrical wave and supplying it to said series circuit.

3. In combination, a plurality of rectifying radiant energy responsive devices, a source of alternating current, means for connecting said source with said devices, one device being reversed with respect to another, means for amplifying the current supplied by said source to said devices, a device operative in one direction or the other in response to the polarity of the current supplied thereto and a non-linear resistor connected in circuit with said device and said amplifying means.

4. In combination, a plurality of rectifying photo-electric devices, a source of alternating current, means for connecting said source with said devices, one device being reversed with respect to another whereby an unsymmetrical wave is produced in response to an unequal illumination of said devices, an amplifier for said wave, a polarity responsive device and a non-linear resistor connected in series with said amplifier and said polarized device.

5. In combination, a source of alternating current, a plurality of similar photo-electric tubes connected to be supplied in parallel from said source and reversely arranged whereby the positive and negative half cycles of said current vary in accordance with the relative illumination of said tubes, an amplifier having its input circuit connected to be energized by said current, a device operative in one direction or the other in response to the polarity of the current supplied thereto and a non-linear resistor connected in a series circuit with said device and the output circuit of said amplifier.

6. In combination, a plurality of radiation responsive devices adapted to receive intermittent radiation, an impedance member, means for producing a current flow through said member in one direction or the other in accordance with relative amounts of said intermittent radiation received by said devices, means for amplifying the potential difference across said impedance member, an electro-responsive device operable in one direction or the other in accordance with the polarity of the current supplied thereto and a non-linear resistor connected in series with said electro-responsive device to receive the output of said amplifying means.

'7. In combination, a plurality of radiation responsive devices adapted to receive intermittent radiation, a reactor, means for producing a current flow through said member in one direction or the other in accordance with relative amounts of said intermittent radiation received by said devices, an amplifier having its input circuit connected across said reactor, a zero center indicator and a non-linear resistor connected in a series circuit with said indicator and the output circuit of said amplifier.

HOWARD I. BECKER. 

